The opening chapter is an important opportunity to set your stall out in non-fiction and establish what it is that your book is all about. It should be clear in its intentions and set the reader on the path that you hope they will see through. A more formal Introduction might be chosen for this purpose instead, but if omitting this, the first chapter, while establishing that road map, should be enticing enough that readers elect against bailing out of your book and hopping into another. To use a foodie analogy, it can be seen as an appetiser tasty enough to persuade the diner to progress to the main course and dessert, instead of encouraging them to walk out without paying, while regurgitating a less than satisfactory entrée.
Fiction, I believe, can be a different proposition. As with non-fiction, the opening chapter can act as a strong marker for what will follow as the story unfolds, or it may throw the reader a creative curveball in appearing to establish a fairly prescribed path, only to veer off onto another that takes them in a totally different direction. Personally, I prefer the latter, providing that change in direction seems viable and hasn’t been crowbarred in, to insert a twist that falls flat on its face.
The first chapter should be used to establish a strong protagonist in fictional works. It is here that the author can at least hint as to their motivations and set in motion their arc, however unpredictable that may ultimately turn out to be. While some authors may prefer not to disclose their protagonist’s physical characteristics, I like to have an image in my mind of what they look like, and know what drives them; what it is that they’re trying to achieve, and what it is that they most definitely want to avoid (and will hopefully meet, in some form, by the end of the story, in order that I can visualise how they react).
The best books I’ve read are those that have hit the ground running, captivating me to the extent that I have no choice but to carry on reading. When assessing manuscripts, I can generally discern from the opening chapter whether or not it’s something that I want to work on. That’s not to say that they don’t have value if they’re not quite what I’m looking for – of course they do, and in particular to whoever created them.
Other people might love them in a way that I can’t, or the subject matter might fall outside of the areas in which I prefer to work, so I try not to be overly judgemental when assessing somebody else’s creation. And, of course, the opening chapter, like any other part of a manuscript, can be rewritten to inject a little more bite into it and really capture the reader’s imagination; though I would suggest that it has a particular function because, like first impressions generally, it can make or break an author’s connection with their audience. And, turning again to my foodie metaphor, that connection should ideally see them sit through, and thoroughly enjoy, the meal you’ve provided for them, and continue to digest it long after they’ve left your eatery.